Prospects on Fabrication of Biopolymer Based Piezoelectric Materials for Green Energy Harvesting

Electro spun web and Solution cast films were made from natural piezoelectric material including PLA, Chitosan, and Cellulose as pure and in composite forms. The morphology and piezoelectric power generation capacity of the materials were observed simultaneously, using an oscilloscope. To evaluate the performance of the composite piezoelectric Nano-generator (NG) as capable energy harvester some light-emitting diodes (LED) were tried to glow. As a result, success was achieved only with PLA/chitosan composite based piezoelectric NG when the solvent used is trifluoro acetic acid (TFA). Blending PLA and Chitosan in other solvent systems including DCM(Dichloromethane), DMSO (Dimethyl Sulfoxide), Formic Acid, Acetone, and different proportions of Acetic acid causes the problem in proper film-formation due to opposite nature of PLA and chitosan, i.e., PLA is hydrophobic and Chitosan is hydrophilic. Chitosan and cellulose, two materials with the same nature had been tried with cellulose in the form of MCC (microcrystalline cellulose). Chitosan/cellulose composite shows no such increase in piezo power as compared to 100% chitosan films due to lack in the orientation of dipoles. Furthermore, electrospinning can help in the alignment of dipoles, but the size of MCC is too large to pass nozzles used in electrospinning. NCC are manufactured using raw cotton. Their higher crystallinity value and relatively small size than MCC can be easily used in electrospinning. However, a co-spinning agent PVA (Polyvinyl Alcohol) to be used to make chitosan electro spinnable.